1. Field of the Invention
The present invention relates generally to vehicle bumper beam designs. More particularly, the invention discloses a vehicle bumper design exhibiting a swept profile combined with an inward forming or “crushing” of either or both of the front and rear wall surfaces associated with the bumper. In one particular application, such crushing of opposite front-end walls, in a direction towards the rear bumper end walls, and without affecting the same, enables the bumper to “meet” the fascia in a close tolerance fashion.
2. Description of the Prior Art
The prior art is well documented with examples of roll-formed bumper bars and bumper assemblies, in particular for use as front and rear vehicle bumpers. An object of such bumper assemblies is to provide an arcuate, or swept, profile which matingly engages the vehicle and in order to provide, to the degree possible, seamless alignment with respect to adjoining locations of the vehicle fascia.
U.S. Pat. No. 5,306,058, issued to Sturrus et al., teaches a bumper bar for vehicles which is formed from a rolled sheet steel and includes a closed tubular profile designed to exhibit a high impact resistance, a high strength-to-weight ratio, and a low cost of manufacture. The bar is preferably swept along its longitudinal axis and in to create an overall curvature consistent with modern automotive designs.
U.S. Pat. No. 6,349,521, issued to McKeon et al., teaches a vehicle bumper beam exhibiting a non-uniform cross section. An associated method for producing a bumper bar includes roll-forming and sweeping a tubular beam with a constant longitudinal cross section, and then reforming the tubular beam to form a tubular beam having a non-constant cross section. The non-constant cross section exhibits specific shapes chosen to provide particular structural properties and surfaces along the reshaped beam, as well as to provide a stylized appearance, such that the reformed beam is useful as a vehicle bumper. The reshaped beam also includes integrally formed vehicle mounting structure, angled end sections forming aerodynamic but impact resistant bumper ends, and a high energy absorbing but flexible center section.
U.S. Pat. No. 6,352,297, issued to Sundgren et al., teaches a vehicle bumper bar extended in one dimension, has a closed cross section and two ends and includes at least one front flange, one rear flange, one top side and one bottom side. The bumper bar has at least one part of the rear flange, lying along the bar, in contact with at least one part of the front flange, also lying along the bar. In the method for manufacturing the bar, the at least one part of the rear flange is wholly or partially pressed in towards the at least one part of the front flange.
U.S. Pat. No. 6,042,163, issued to Reiffer, teaches a vehicle bumper bar having a swept B-shaped beam section and one-piece end pieces attached to opposing ends of the beam section for forming a compound angle along a front of the bumper bar. The end pieces are tubular and include circumferentially overlapping flanges that allow the shape of the end piece to be circumferentially adjusted to a best-fit condition on the ends of the beam section.
Further included are attachment tabs that longitudinally engage the ends of the beam section. The attachment tabs extend from the end piece longitudinally and circumferentially onto the beam section, in order to provide optimal impact and attachment strength of the end piece on the beam section. A method includes positioning the end piece on an end of the beam section, clamping the end piece onto the end including shaping the end piece circumferentially to a best-fit shape, and securing the end piece to the beam section by welding.
Finally, U.S. Pat. No. 6,695,368, issued to Weykamp et al., teaches a tubular beam having front, top, bottom and rear walls, and further having open tubular ends. The bumper system includes a pair of mounting brackets each having a V-shaped mounting section attached to the rear wall of the open tubular ends and having an integral corner-forming section extending from the mounting section laterally around the associated ends and forwardly to a location where the corner-forming section attaches to the front wall of the one end. The corner-forming section includes a resilient portion shaped to flex and absorb energy upon corner impact, and further is adapted to transfer energy directly to the vehicle frame, thus providing efficient and effective energy absorption upon corner impact.